From b96381c56ef17bd3b79cf3e780afa19a39201cc0 Mon Sep 17 00:00:00 2001
From: Yingjie Wang <phywyj@gmail.com>
Date: Sun, 7 Dec 2025 17:14:40 -0500
Subject: [PATCH] fix: rng performance

---
 src/render.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/render.c b/src/render.c
index fc26990..b1e95fc 100644
--- a/src/render.c
+++ b/src/render.c
@@ -3,6 +3,7 @@
 #include <gsl/gsl_rng.h>
 #include <gsl/gsl_spline.h>
 #include <gsl/gsl_monte_miser.h>
+#include <math.h>
 #include <stdio.h>
 #include "render.h"
 
@@ -101,11 +102,10 @@ int pixel_render(const System *system, int i, int j, const Spline_data spline_da
 
 int render(System *system, double *buffer, int pixel_render_max, double pixel_render_err, double chi_rela_err) {
   double h = (system->H)*(system->w)/(system->W);
-  double tanpsi2 = (system->w)*(system->w)+h*h;
-  double cotpsi2 = 1/tanpsi2;
+  //double tanpsi2 = (system->w)*(system->w)+h*h;
+  //double cotpsi2 = 1/tanpsi2;
   //double bmax = R0/sqrt(f(R0)*(1+cotpsi2));
-  double rmax = sqrt(tanpsi2);
-  gsl_rng *r = gsl_rng_alloc(gsl_rng_default);
+  double rmax = hypot(system->w, h);
  
   double *x=NULL;
   double *y = NULL;
@@ -122,6 +122,7 @@ int render(System *system, double *buffer, int pixel_render_max, double pixel_re
   {
     gsl_interp_accel *acc = gsl_interp_accel_alloc();
     Spline_data spline_data = {spline, acc};
+    gsl_rng *r = gsl_rng_alloc(gsl_rng_default);
     
     #pragma omp for
     for(int j = 0; j < H; j++) {
@@ -131,6 +132,7 @@ int render(System *system, double *buffer, int pixel_render_max, double pixel_re
     }
 
     gsl_interp_accel_free(acc);
+    gsl_rng_free(r);
   }
   return 0;
 }